Sorry Arct1k, no template. I just took a piece of bar stock and shaped it by eye.
Update:
DONE! Yay! It's been sitting with unfinished battery trays for a couple months now, but got around to finishing it. Came up with a battery tray scheme that is adjustable; accomodates lipo packs that are 80-110mm wide and 147-167mm long (150-170mm without foam pads). The length is adjustable by moving the front tray forward by 20mm.